Cytology is the most important, as well as the most fascinating, department
of physiology and pathology. Though it is doubtful if we shall ever arrive
at a perfect solution of the structure and functions of the cell, since all
our means of investigation change its nature and put to flight that subtle
something within its substance which we call vitality,
our labors have nevertheless been sufficiently rewarded by revelations so
startling as to stimulate us to further investigation.